Mud motors utilize fluid energy converted to mechanical energy to provide shaft rotation to a drill string or drill bit. Because the mud motor is a highly loaded section of a drilling tool, it is prone to critical damage during driveshaft transmission failure. Failure of the driveshaft transmission may result in critical damage to the transmission assembly, including the separation of components from the transmission assembly. Where such separation occurs, these components may be lost downhole. The lost components dropped downhole can prevent further progression in drilling and can cause significant delays. The loss of components downhole may even result in a drilling project being abandoned. A procedure known as “fishing” is sometimes used to retrieve the lost components, but this procedure is costly and time-consuming, and may be ineffective. A catch assembly may be included in a driveshaft transmission assembly to prevent the loss of drilling components downhole. But, preventing the loss of drilling components downhole may require components of the driveshaft transmission assembly to be directly coupled with the catch assembly or indirectly coupled with the catch assembly (e.g., coupled with a component of the driveshaft transmission assembly that is coupled with the driveshaft) to allow the catch assembly to retain the components in the event of separation.